Adult-Gerontology Clinical Nurse Specialist (CNS) Practice Exam

Which of the following describes how well a drug passes through natural body barriers in older adults?

1. Metabolism

2. Absorption

3. Excretion

4. Distribution

The correct answer is: Absorption

The correct response relates to absorption, which refers to the process by which a drug enters the bloodstream after administration. In older adults, physiological changes such as decreased gastric pH, slower gastric emptying, and altered gastrointestinal motility can significantly impact how well a drug is absorbed. This demographic often experiences these changes, which can lead to differences in the pharmacokinetics of medications. Understanding absorption is critical in geriatric care because it influences the overall efficacy and safety of drug therapy. When prescribing medications for older adults, healthcare providers must consider these age-related changes in absorption to avoid subtherapeutic effects or toxicity. Metabolism, excretion, and distribution are also essential components of pharmacokinetics, but they pertain to different phases of how a drug is processed after it enters the bloodstream. Metabolism involves the biochemical modification of drugs, excretion deals with the elimination processes largely via the kidneys and liver, and distribution encompasses how the drug disperses throughout the body's tissues. Each of these processes can also be altered in older adults, but when specifically discussing how well a drug passes through natural body barriers, absorption is the most relevant aspect.